A demonstrator wears a "Make America Trade Again" hat close to the Presidential Palace in Helsinki, Finland, on Monday, July 16, 2018. U.S. President Donald Trump prepared to meet Russian President Vladimir Putin in Helsinki on Monday, under pressure to confront his Russian counterpart over Kremlin meddling in the 2016 election and with concerns rising that the U.S. is abandoning the current international order. Photographer: Chris Ratcliffe/Bloomberg

The reckoning from President Trump’s trade war was previewed Wednesday as the three U.S. automakers posted lackluster second-quarter earnings and warned that the next six months could be worse.

GM shares fell 4.6% by Wednesday's close of trading, after reducing its guidance for its full year earnings to $6 per share from a previous range of $6.30 to $6.60. CEO Mary Barra and Chief Financial Officer Chuck Stevens attributed the lower forecast to a combination of foreign currency devaluations, mostly in South America, and higher prices for commodities such as steel and aluminum.

While both tried not to tied the higher costs to Trump’s tariffs, Barra closed a conference call with analysts by saying, “It’s in everyone’s best interest to have a strong U.S. auto industry, because it accounts for a lot of jobs.”

Stevens put it a little differently.

“We are in a very uncertain and volatile environment,” he said.

At Fiat Chrysler, which is mourning the death of CEO Sergio Marchionne, new CEO Mike Manley said the company has fixed-price contracts for most of its steel and aluminum purchases, but that higher prices could hit early in 2019.

FCA said adjusted earnings before interest and taxes for the three months ended June 30 fell 11% to 1.7 billion euros ($2 billion), compared with 2 billion euros in a Reuters poll of analysts.

Ford Chief Financial Officers Bob Shanks said tariffs, including the 25% on imported steel and 10% on imported aluminum that the Trump administration imposed June 1 will cost Ford about $1.6 billion this year in North America alone.

Ford's second-quarter earnings tumbled nearly 50% from a year earlier to $1.07 billion, or 27 cents per share. The average analyst estimate was that the Dearborn automaker would earn 31 cents per share. The company blamed smaller profit margins in China, where it lost $483 million in the second quarter, and a fire at a supplier plant that resulted on one week of lost production of the profitable F-Series pickup trucks.

Some of the factors are cyclical. The U.S. industry is coming off three straight years of more than 17 million vehicles sold. The hottest segments – compact and midsize SUVs -- are glutted with dozens of models that look alike, and customers are holding out for the best possible deal as interest rates rise and incomes don’t.

Adding to the confusion was a late afternoon White House event where President Trump and European Commission President Jean-Claude Juncker announced a trade truce of sorts. The two agreed agreed to continuing negotiations aimed at reducing tariffs and other trade barriers, and for the Europeans to buy billions of dollars of American exports, from soybeans to natural gas.

The move defused, for the moment, a trade battle that began with Trump’s tariffs on European steel and aluminum exports and threatened to escalate to its automobiles.

Juncker said the two parties would hold off on further tariffs, and potentially drop the existing ones, unless they fail to agree on a broader agreement.

FCA said it expected 2018 net revenues of between 115 and 118 billion euros, down from a previous forecast of around 125 billion euros,

The larger second-quarter impact came from falling sales and higher incentive spending in China as consumers waited for a reduction in import duties that took effect this month.

FCA shares fell 15% in afternoon trading before rebounding slight to close down nearly 12%.

The situation could get worse, if Trump follows through on his threat to levy the 25% tariff on all imported vehicles.

Only 52% of the cars, SUVs and pickup trucks sold in the U.S. are assembled in the U.S. About half of those, or 25% of all sales, are produced in the U.S. plants of Asian and European automakers.

Half of the 48% that are imported are assembled in Canada and Mexico, where the North American Free Trade Agreement has minimized tariffs in order to allow a free flow of parts across borders multiple times. Trump administration trade officials have indicated no interest in extending NAFTA. While bi-lateral talks could continue with Canada and Mexico on separate paths, they are currently suspended.

Then there is the likely retaliation that would come from Europe, Japan and China.

Last year U.S. automakers, including the Asian and European companies, and their suppliers exported more than $100 billion of vehicles and parts to 88 other countries. That market would be much smaller in a trade war.

Trump met with European Commission President Jean-Claude Juncker Wednesday, but there is little evidence of a compromise.

Last week the overwhelming majority of people speaking at a Commerce Department hearing about whether all imported vehicles threaten U.S. national security opposed the 25% tariff. It is unclear whether that testimony will have any impact on Trump’s decision.

“Tariffs are the greatest.” Trump tweeted earlier this week. In Detroit, Munich, Stuttgart and Tokyo there’s less enthusiasm.